Journal des nanosciences : recherche actuelle

I am pleased to introduce International Journal of Nanosciences: Current Research (JNCR) which is an open access electronic journal aiming to provide an online compendium for Nano science Research & Technology. The interdisciplinary coverage of the Journal includes all the basic and applied research of Nano scale sciences with innovative Nanotechnology applications towards science, engineering and technology. We have been started in year 2016. Journal of Nanosciences: Current Research (ISSN: 2572-0813) is growing continuously. It is our pleasure to announce that during year 2019, all issues of volume 12 were published online on time and the print issues were also brought out and dispatched within 30 days of publishing the issue online.

All published articles of this journal are included in the indexing and abstracting coverage of Index Copernicus, Google Scholar, Sherpa Romeo, Academic Journals Database, Open J Gate, Genamics Journal Seek, Academic Keys, ResearchBible, Directory of Open Access Journals, VieSearch, China National Knowledge Infrastructure (CNKI), Electronic Journals Library, RefSeek, Directory of Research Journal Indexing (DRJI), EBSCO A-Z, OCLC- WorldCat, SWB online catalog, Publons, Advanced Science Index, Secret Search Engine Labs.

During the calendar year 2019, Journal of Nanosciences: Current Research received a total of 20 papers, out of which 10 articles were rejected in the preliminary screening due to plagiarism or being out of the format and peer review process. During 2019 around 10 articles were subjected for publication after they are accepted in the peer review process. In the 2 issues of Volume 4 published during the year 2019, a total of 10 articles were published (at an average of 5 articles per issue of which, articles were published from authors all around the world. A total of 25 research scientists from all over the world reviewed the 10 articles published in volume 4. Average publication period of an article was further reduced to 14-21 days.

During the calendar year 2019, a total of three Editors, ten Reviewers joined the board of JNCR and contributed their valuable services towards contribution as well as publication of articles, and their valuable reviewer comments will beneficial to publish quality of article in the Journal.

I take this opportunity to acknowledge the contribution of Editor-in-chief and Associate Editor during the final editing of articles published and bringing out issues of JNCR in time. I would also like to express my gratitude to all the authors, reviewers, the publisher, language editor, honorary editors, the scientific advisory and the editorial board of JNCR, the office bearers for their support in bringing out the new volume (Volume 5) of JNCR for the calendar year 2020 and look forward to their unrelenting support further to release more issues for Journal of Nanosciences: Current Research (JNCR) in scheduled time.

Silver nanoparticles (AgNPs) are widely spread worldwide for several centuries and are extremely utilized in industry, cosmetics, food packaging for its proposed antimicrobial activities. Many reports mentioned the good value of AgNPs in many faces. This review focused on antimicrobial activities of AgNPs, subjecting briefly to their synthesis, with a special specialise in different mechanisms of action and factors affecting these activities as an antimicrobial agent.

Introduction: Increasing hospital and community-acquired infections thanks to bacterial multidrug-resistant (MDR) pathogens that current antibiotic therapies aren't effectively to represent a growing problem. Antimicrobial resistance is, thus, one among the main threats to human health, since it determines a rise of morbidity and mortality as a consequence of the foremost common bacterial diseases. Resistance genes have recently emerged, favored by improper use of antibiotics; hence, the primary step in combating resistance envisions the reduction of antibiotic consumption. Antimicrobial resistance may be a complex mechanism whose etiology depends on the individual, the bacterial strains and resistance mechanisms that are developed. The emergence of resistance against newly developed antibiotics further supports the necessity for innovation, monitoring of antibiotic consumption, prevention, diagnosis and rapid reduction within the misuse of those drugs. it's thus necessary to optimize antibiotics’ pharmacokinetics and pharmacodynamics so as to enhance treatment outcomes and reduce the toxicity and therefore the risk of developing resistance. to deal with the matter of resistance, it'll be necessary to vary the protocols of use of antimicrobials in order that these drugs are administered only all other treatment options have failed and joint efforts of governments and academic networks are needed to fight against the globally spreading of multidrug-resistant pathogens. Today, there's a requirement to hunt alternative treatments. Non-traditional antibacterial agents are thus of great interest to beat the resistance that develops from several pathogenic microorganisms against most of the commonly used antibiotics. AgNPs are used for several centuries as a biocidal in US in 1954. The guide for silver use silver antimicrobial was traditionally from many centuries in ancient Egypt and Rome. Ancient Egyptians were believed within the healing power and anti-microbial effects of silver power by using it before antibiotics; also the Phoenicians used the silver vessels for water and wine preservation during their long voyages. the primary report for the medical use of silver was as an eye fixed solution in 1884 by the utilization of 1% (AgNO3) (Russell and Hugo 1994). Recently, silver compounds is suggested topically as antibacterial cream for burn wounds and still used till now. However, some cytotoxic effects and lots of limitations to the clinical use of silver materials are reported. In China, AgNPs were used for its antimicrobial action in many places as elevators and railway stations various forms (organic and inorganic), but the mostly stable one are +0 and +1, although it also exists in (+2, +3) forms AgNPs differs consistent with sizes (1-100 nm), shape(wires, spheres, triangles, rods), and coatings (polymer, peptide, sugars, citrate) but most forms are derived from nitrate which is that the main agent use within the synthesis of AgNPs. Modern advances in nanotechnology, improved the assembly of silver at nanoscale vercoming many cytotoxic limitations with a broad use in many applications including electronic and transparent conductor applications, antimicrobial effects in goods and medical products which leads the expansion of the nanosilver market. The sole fact about Silver is that the highly toxicity of it and related compounds against many microorganisms. This fact reflects the main roles of AgNPs in medical applications. The foremost predominant sort of silver is nitrate , but the nanoparticle form provides major advantage by presence of more area for microbe exposure which opens the door about many various uses for its antibacterial action.

The unique physical, chemical and biological characters of AgNPs attracted the interest compared to usual macro silver. AgNPs differs completely in their properties from silver as they has higher catalytic activity, higher chemical stability and better electrical and thermal conductivity which makes them of potential value in many applications like inks, microelectronics, and medical imaging.

Metals alloys are of great technological interest which can even increase if they're nanostructured. Also, it are often found within the literature, an equivalent proposed chemical synthesis methodologies obtain different sorts of materials with nanocrystal particle content. Then, the most objective of this work was to get a CuNiCo alloy, by an alternate procedure capable of generating nanostructured grains, followed by its preliminary characterization. it's been done by dividing the method into two steps the primary one is that the thermal decomposition of a nitrate solution [Cu(NO3)2, Ni(NO3)2 and Co(NO3)3] getting to obtain a homogeneous co-formed metal oxide. within the second step, these oxides are heated to the specified temperature and kept during a reductive flow of hydrogen, leaving the CuNiCo alloy as final product. The applied reduction temperatures were 300°C and 900°C. The materials obtained after each step were characterized by scanning microscopy (SEM) and energy dispersive X-ray detector (EDS). As a results of the primary step, it had been found that oxygen, Cu, Ni, and Co were, as desired, homogeneously distributed, as shown within the SEM elemental mapping. The after reduction obtained material present different shape and particle size, counting on the applied reducing temperatures. The more circular and greater size observed at 900°C confirms an increased sintering occurrence at a better temperature and therefore the EDS results indicate the expected composition for Co, Ni and Cu. The initial results given by transmission microscopy (TEM) have shown the presence of particles with spherical morphology and a homogeneous distribution of the weather , which are sharing an equivalent crystal structure. Also, it had been noted the presence of particles smaller than 100 nm within the CuNiCo alloy.

Introduction: Much work is presently being done round the world to develop hydrogen and fuel-cell technologies in order that they're going to be cost-competitive in diverse applications. Platinum works well as a catalyst in hydrogen fuel cells; however, it's a minimum of two drawbacks therein it's expensive and degrades over time. Eliminating the valuable metal platinum would solve a big economic challenge that has thwarted the widespread use of large-scale hydrogen fuel-cell systems. a replacement catalytic material supported the element cobalt has been proposed as an alternate to platinum in recent years and might allow the manufacturing of cheaper and more durable hydrogen fuel cells. Cobalt is taken into account to be the primary catalyst made up of nonprecious metal with properties closely matching with those of platinum. Cobalt serves also as a model system for the macroscopic magnetic response; because the low to moderate crystal anisotropy allows the consequences of size, shape, internal crystal structure, and surface anisotropy to be observed during a single system. The low crystal anisotropy of cobalt also promotes their study as a model system for the consequences of size, shape, crystal structure, and surface anisotropy on their macroscopic magnetic response. a spread of methods for the preparation of magnetic colloid dispersions are reported. Cobalt is one among the foremost important ferromagnetic metals thanks to its three metastable phases with different crystallographic structures, namely, the hexagonal closed packed (hcp) phase, the face-centered cubic (fcc) phase, and therefore the epsilon phase.

Synthesizing metallic nanoparticles following wet-chemistry routes may be a powerful way of obtaining a reproducible macroscopic amount of homogeneous sample. Several wet-chemical methods are developed to synthesize cobalt crystals with different morphologies, for instance, pyrolysis, solvothermal and hydrothermal decomposition, microfluidic synthesis, modified polyol processes, and template-based methods. it's been reported that liquid-phase reduction methods are relatively simple and don't require special equipment. Moreover, they're considered to be less costly and quicker to implement, which are desirable qualities for future attempts of large-scale production.

Mesoporous materials are applied in various fields like catalysts, supports for nanomaterials, adsorption and separation, and sensors. one among the details for a few applications is to regulate the pore size or the pore structure counting on the aim. it's necessary to regulate the dimensions of the pores consistent with the dimensions of the molecules or substances entering the pores of the mesoporous material. Also, it's vital that the change of the fabric constituting of the skeleton and therefore the properties of the mesoporous material counting on the aim of use. The mesoporous carbon material is predicted to be applied in fields like electrode materials of a cell because it's a area of 1,000 to 2,000 m2/g, excellent thermal stability, absorption and performance as a carrier. Especially, mesoporous materials are mostly utilized as catalysts or adsorbents because they need uniform nanopores. Despite its many advantages, the carbon material is weak in strength counting on the orientation and is definitely cracked and features a low applicability generally . during this study, a mesoporous carbon membrane supported silica nanoparticle was prepared. Various synthesis parameters were systematically investigated to review the consequences on the dimensions and therefore the size distribution of silica nanoparticles. The silica nanoparticles were pressurized into a disk then calcinated to get a mesoporous carbon membrane. Then the membrane was chemically treated with COOH group, and Ag was complexed on the surface of the membrane. additionally , our study suggests a replacement method to repair the metal to the surface of the mesoporous carbon membrane also on increase the strength of them.

Introduction: Modern nanotechnology has evolved because the principal component of science within the current century. Over the years, diagnosis of diseases and its therapy is consistently leaping milestones thanks to the application of nanotechnology within the field of biomedicine. The evolution of nanomedicine and green technology for its production has been an excellent boon and have shifted paradigms in therapy and tissue engineering, due to the benefits of nanocarriers like a high area to volume ratio, unique features of surface modification and engineering to get particles of varied sizes, shapes and different chemical characteristics. These have proven to be biocompatible, biodegradable and non-toxic which adds to its advantages. Lipid-based nanocarriers, polymeric nanoparticles, dendrimers have revolutionized the therapy for various conditions especially cancer and infectious diseases. Many of those products are approved and are commercially available. Apart from the above mentioned organic nanoparticles, inorganic nanoparticles have also been widely explored for his or her application in biomedicine. Out of them, quantum dots, iron oxide nanoparticles are approved and are commercially available. Carbon dots, nanoparticles of gold, silver, various other metal oxides, layered double hydroxide nanoparticles and silica nanoparticles have been widely used for various diagnostic and therapeutic purposes. Of these, silica nanoparticles comprising of organic dyes and radioactive iodide referred to as Cornell dots (C dots) has successfully attained a crucial benchmark of safety by its approval for phase I clinical trial human trials which is vital for any substance requiring Investigational New Drug (IND) approval. C dots are core-shell silica nanoparticles containing fluorescent molecules within the silica core surrounded with silica shell which is further coated with polyethylene glycol (PEG). C dots were first developed by Spencer T. Olin Professor of Engineering, Ulrich Wiesner from Department of Materials Science and Engineering at Cornell University. Silica nanoparticles with mesopores–referred to as mesoporous silica nanoparticles (MSNs)–have gained wide popularity over the recent years. Its advantages of uniform and tunable pore size, easy independent unctionalization of the surface, internal and external pores and therefore the gating mechanism of the pore opening make it a particular and promising drug carrier.

We have developed facile CVD techniques for the synthesis of metal hybrid nano-catalysts used for cell or secondary battery. By using the CVD technique, we will easily obtain the right catalytic structure and manipulate the microstructure of the nanometal catalysts. it's noteworthy that the traditional multi-step synthetic processes are often simplified into a single-step process or a sequential process by these processes. For the single-step CVD synthesis of Pt nanocatalyst decorated with porous graphene shells, MeCpPtMe3 was used as a precursor of Pt nanoparticles. For the synthesis of graphene shells, various hydrocarbon precursors like acetylene, acetone or ethyl alcohol were used as precursors, which were vaporized and simultaneously flowed into the CVD reactor. For the low-temperature synthesis of bimetallic nanoalloys for cell electrode, we applied a one-pot sequential CVD technique. For the synthesis of Pt-Co bimetallic nanoparticles, MeCpPtMe3 was vaporized and flowed into a CVD reactor, where lampblack was placed as support of Pt-Co bimetallic catalyst. For Co deposition, CpCo(CO)2 was vaporized and flowed into the CVD chamber. Then, the Pt with Co nanoparticles deposited on lampblack was annealed for the synthesis of Pt3Co bimetallic nanoparticles. By single-step CVD technique, Pt with porous graphene shells was synthesized, which showed higher efficiency compared to reveal Pt and maintaining long-term stability after extended potential cycling which is thanks to the protective effect of graphene shells. Also, our sequential CVD techniques for bimetallic Pt-Co nanocatalyst are efficient for the fast , simple and straightforward synthesis of optimal catalytic structure. this system is extremely useful for lowering the synthetic temperature of metal alloys by quite 200°C compared to standard processes.

Introduction: Very intense research activities are devoted during the past decade to the elaboration of hybrid nanoparticles so as to together several complementary properties within the same very small object. As a first example, Weissleder reported pioneering works handling the event of triple label nanoparticles.1Core/shell structure nanoparticles supported polysiloxane coated gadolinium oxide doped with Tb3+ions were found to beefficient for the detection of biomolecules.2As another example, iron oxide nanoparticles coated with a PEGylated copolymer were prepared and used as contrast agents for in vivo resonance imaging (MRI).3In an equivalent way, multimodal contrast agents for MRI were developed from the previously described hybrid nanoparticles supported Gd2O3coated with a polysiloxane shell, encapsulating an organic fluorophore and carrying PEG chains onto their surface.4More recently, it had been also demonstrated that adding gold inclusions within silica particles containing fluorescein allows the suppression of the self-quenching phenomenon. All of those examples illustrate well the concept of a multifunctional hybrid platform, namely a really small object engulfing organic and/or inorganic nanoparticles and displaying additional functionalities like a stealthy character, a molecular recognition, or reduced toxicity by pertinent coating. additionally, the colloidal stability of those nano-particles over an extended period has got to be ensured. Some interesting coatings could also be planned so as to fulfill two requirements simultaneously, the simplest known of them being PEG: additionally to he steric stabilization, the PEG coating reduces the detection of nanoparticles or liposomes by the system then the reticular endothelial uptake of nanoparticles, thus increasing their circulation time within the body. Therefore, the final properties and further applications of these multifunctional hybrid platforms are closely related to their surface chemistry, which needs to be well-controlled.